Slitherine

These are the current values:
WINTER_DURATION 5 /*how many turns severe winter in Russia last. Start time random from October till January */
/* Variation of severe winter length */
CHANGE_FOR_DURATION 60 /* 0..100. Accumulated chance that length = WINTER_DURATION. % chance = 60 */
CHANCE_FOR_DURATION_MINUS_1 80 /* 0..100. Accumulated chance that length = WINTER_DURATION - 1. % chance = 20 */
CHANCE_FOR_DURATION_MINUS_2 90 /* 0..100. Accumulated chance that length = WINTER_DURATION - 2. % chance = 10 */
CHANCE_FOR_DURATION_PLUS_1 100 /* 0..100. Accumulated chance that length = WINTER_DURATION + 1. % chance = 10 */

2. Proposed change to:
CHANGE_FOR_DURATION 60 /* 0..100. Accumulated chance that length = WINTER_DURATION. % chance = 60 */
CHANCE_FOR_DURATION_MINUS_1 80 /* 0..100. Accumulated chance that length = WINTER_DURATION - 1. % chance = 20 */
CHANCE_FOR_DURATION_MINUS_2 80 /* 0..100. Accumulated chance that length = WINTER_DURATION - 2. % chance = 0 */
CHANCE_FOR_DURATION_PLUS_1 100 /* 0..100. Accumulated chance that length = WINTER_DURATION + 1. % chance = 20 */

3. Proposed change to:
CHANGE_FOR_DURATION 60 /* 0..100. Accumulated chance that length = WINTER_DURATION. % chance = 60 */
CHANCE_FOR_DURATION_MINUS_1 70 /* 0..100. Accumulated chance that length = WINTER_DURATION - 1. % chance = 10 */
CHANCE_FOR_DURATION_MINUS_2 70 /* 0..100. Accumulated chance that length = WINTER_DURATION - 2. % chance = 0 */
CHANCE_FOR_DURATION_PLUS_1 100 /* 0..100. Accumulated chance that length = WINTER_DURATION + 1. % chance = 30 */